The use of personal communication devices has increased astronomically over the last two decades. The penetration of mobile devices in modern society has continued to drive demand for a wide variety of networked devices in a number of disparate environments. The use of networked devices using 3GPP LTE systems has increased in all areas of home and work life.
In many instances, it is desirable to allow various communication devices, including user equipment (UEs) and enhanced Node Bs (eNB), to simultaneously communicate using multiple access schemes to improve system capacity. A number of such multiple access schemes and waveforms (e.g., Orthogonal Frequency Division Multiplexing (OFDM), Discrete Fourier Transform-Spread-Orthogonal Frequency Division Multiplexing (GI-DFT-s-OFDM), single carrier (SC), etc.) may permit concurrent data transfer of multiple types between the network (e.g., eNB) and UE or between different UEs (device-to-device, also called D2D). Rather than being designed for a particular modulation scheme or waveform however, communication systems may be flexible enough to ensure operation with different types of modulation schemes and waveforms.
In the US, the current generation of systems is 3GPP 4G standard LTE. Efforts have already begun on developing the next 3GPP (5G) generation system. It may thus be desirable to provide a downward-compatible 3GPP 5G multiple access scheme that provides relatively high capacity, low latency, and low control overhead while taking into account receiver complexity.